Ultra high quality factor optoelectronic oscillator stabilized with acousto optic cells

International audienceTeO2–crystal–based acousto-optic cells allows the stabilization of an optoelectronic oscillator (OEO). The system is operating for any resonator to be inserted into the OEO with a Q-factor from 2x10^7 to 10^11

Investigation in acousto-optic laser stabilization for crystal resonator-based optoelectronic oscillators

International audiencePotentialities are investigated for using acousto-optic cells based on a TeO2 crystal to stabilize a microwave signal generated by an optoelectronic oscillator. Bulk acoustic waves at two radio frequencies (RF) near 60 MHz are launched in the two identical cells providing a required locking on of a microwave signal. Differences between RF signals are up to 400 kHz to follow quality factor of the optic resonator typically in the range of 5×108. Critical alignment of the two cells is performed thanks to an extraordinary polarized laser beam launched at a very low Bragg angle of light incidence. Moreover, the system is operating for any resonator to be inserted into the optoelectronic oscillator with a Q factor in the range of 2×107−1011

Realities and prospects of distance learning at higher education institutions of Ukraine

The paper deals with the issue of realities and prospects of distance learning at higher education institutions of Ukraine. Distance learning in Ukraine has been implementing for more than twenty years and distant learning technologies are used at most Ukrainian higher education institutions, but the necessity and feasibility of the introduction and development of remote technology is questionable both to faculty and students. The main purpose of this paper is to synthesize the real state of distance learning in Ukraine and outline its development prospects at higher education institutions of Ukraine. The paper represents the analysis of the survey results of student answers of four classical, pedagogical, maritime and agrotechnological higher education institutions regarding the practical implementation of distance learning in their institutions. The study of the realities of distance learning in the practice of higher education institutions in Ukraine has been conducted among 102 students. The questions concerned student attitude to distance learning, distance learning organisation, advantages and disadvantages of distance learning

The moral discourses of ‘post-crisis’ neoliberalism: a case study of Lithuania’s Labour Code reform

This article problematizes the neoliberal reconfiguration of labour rights in Lithuania, a newer European Union member state, in which the impacts of the global economic and financial crisis were particularly severe and where radical austerity measures were subsequently imposed. Now, after six years, in an attempt to resolve the exhaustion of previous austerity-based solutions for economic recovery, a new Labour Code is being introduced which will further weaken labour protections and labour rights. This article analyses conflicting positions in current debates over Labour Code reform. It attempts to map the mobilization of strategic discursive resources in an unfolding dialogical ‘moral’ politics of Labour Code reform in the current conjuncture of ‘post- crisis’. Theoretically, this article draws upon the seminal work of the early Soviet Marxist scholar V. N. Voloshinov in proposing a dialogical method which foregrounds the interconnections of language, class and ideology

"Poof! a'm heppily saving the Lord...": multimodality and evaluative discourses in male toilet graffiti at the University of the Western Cape

This paper explores the use of punctuation, capitalisation, linguistic forms and images in the construction of evaluative discourses in male toilet graffiti at the University of the Western Cape. Of particular interest is how male students use these devises in the discursive construction of the appraisal resource of Attitude, Graduation and Evaluation. Using over 150 tokens of graffiti, the paper uses a multimodal approach employing notions of resemiotisation and remediation to show how taboo language, font size, images and sketches are repurposed to aid the evaluation of the 'self' and the 'other' in toilet graffiti. The paper shows that through utilising multimodal texts, graffiti writers are able to reformulate and situate novel meanings in contexts; and in terms of appraisal, the verbal and non-verbal semiotic material are strategically combined to engender novel evaluations